Shutter operating mechanism having an automatic exposure time control means for photographic camera

ABSTRACT

A photographic camera with an automatic exposure control means, an exposure time control circuit for initiating the closure of the camera shutter and a film frame number indicating mechanism having non-usable and usable frame indications. A shutter closure urging circuit is operably connected into the exposure time control circuit and has connected therein a switch to render effective and ineffective the shutter closure urging circuit. A lever actuates the switch to render effective the shutter closure urging circuit when the indicating mechanism is providing the non-usable frame indication and for rendering ineffective the shutter closure urging circuit when the indicating mechanism is providing the usable frame indication.

Uited States Patent 11 1 Uno et al.

[ Nov.6,1973

[73] Assignee: Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo-to, Japan [22]Filed: July 27, 1972 [2]] Appl. No.1 275,784

[30] Foreign Application Priority Data Aug. 6, 1971 Japan 46/69820 [52]US. Cl 95/10 C, 95/53 E [51] Int. Cl. G03b 9/62 [58] Field of Search95/10 C, 10 CE, 10 CT,

[56] References Cited UNITED STATES PATENTS 3,500,729 3/1970 Rentschler95/53 EB 3,422,738 1/1969 MOrl et al....i 95/10 CT 3,673,4l5 6/1972Yoshimura et al. 95/10 CT 3,326,103 6/1967 Topaz 95/10 CT PrimaryExaminer--Samuel S. Matthews Assistant Examiner-Russell E. Adams, Jr.Att0meyRobert L. Parker et al.

[57] ABSTRACT A photographic camera with an automatic exposure controlmeans, an exposure time control circuit for initiating the closure ofthe camera shutter and a film frame number indicating mechanism havingnon-usable and usable frame indications. A shutter closure urgingcircuit is operably connected into the exposure time control circuit andhas connected therein a switch to render effective and ineffective theshutter closure urging circuit. A lever actuates the switch to rendereffective the shutter closure urging circuit when the indicatingmechanism is providing the non-usable frame indication and for renderingineffective the shutter closure urging circuit when the indicatingmechanism is providing the usable frame indication.

7 Claims, 6 Drawing Figures PATENTEDnav 6 ms 3.769.886 SHEET 20$ 2SHUTTER OPERATING MECHANISM HAVING AN AUTOMATIC EXPOSURE TIME CONTROLMEANS FOR PHOTOGRAPHIC CAMERA BACKGROUND OF THE INVENTION In loading newfilm into a camera, after the film is set into the film transportmechanism, an exposed lead of film is transported by taking fictitiousshots. During the taking of fictitious shots, light which wouldotherwise be incident upon the film is often intercepted by mounting alens cap over the taking lens or simply with the hand, partly fromhabit. As a result, photographic cameras of the type in which theexposure time (shutter open) is controlled according to a photometricvalue (determined by the amount of light coming through the objectivelens from an object to be photographed) is set into a state of exposurefor a long period of time during the taking of fictitious shots. As aresult, a relatively long time is necessary for taking the fictitiousshots and the user may often start the next transport of film carelesslyneglecting the fact that the shutter is still open.

SUMMARY OF THE INVENTION The present invention provides an improvedshutter operating mechanism in which fictitious shots may be easily andsafely taken with the lens covered by eliminating the long period oftime during which the shutter is open.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective and schematicblock diagram view showing a preferred embodiemnt of the mechanismaccording to the present invention;

FIGS. 2 and 3 are plan views of the mechanical portions of the preferredembodiment of FIG. I in different states;

FIG. 4 is a perspective and schematic block diagram view showing analternate preferred embodiment of th present invention; and

- FIGS. 5 and 6 are plan views of the mechanical portions of thealternate preferred embodiment of FIG. 4 in different states.

DESCRIPTION OF THE PREFERRED EMBODIMENT Consider now the details of thepresent invention. As shown in the embodiment of FIG. 1, a conventionalshutter closure starting circuit 1 is included in a conventionalautomatic exposure time control circuit la, the latter of whichdetermines a value of regulated time and controls an electromagnet (notshown) to start shutter closure. Circuit 1 operates in cooperation andunder control of functional circuit elements such as a photosensitiveelement 3 included in a photometric circuit and a source switch 4 forpower source batter 2 in a conventional manner well known in the cameraart. The closure start circuit is controlled in accordance with theamount of light received by photosensitive ele ment 3. A resistor 5 hasa low resistance value in relation to the resistance of the element 3.The resistor 5 is connected in series with a switch 6 of normally openedtype and the resulting serial circuit is connected in parallel withthephotosensitive element 3.

A film frame number indicating mechanism includes an indicator disk 7with a recess 8 and a cam 9 which is connected so as to rotate in unisonwith the indicator disk 7. Adjacent to a peripheral surface of the cam 9there is positioned an operative end of a mechanical linkage or lever 11which is rotatably journaled. Another operative end of the lever 11 isadjacent to a movable contact 6a of the switch 6. A spring 12 isconnected to lever 11 so as to normally bias the lever 11 so that themovable contact 6a is forced against anopposed contact 6b. Therelationship between the first operative end of the lever 11 and therecess 8 of the cam 9 is selected so that the first operative end comesinto the recess 8 when the indicator disk 7 is below the 0 end of thescale and indicates a graduation 7a corresponding to the fictitiousshot.

An alternate embodiment of the present invention is shown in FIG. 4. Thesame numerals used in FIG. 1 are used to designate the same elements inFIG. 4. Switch 6 is replaced by a switch 13 of normally opened typewhich is serially inserted into the circuit with the power sourcebattery 2, the time control circuit la, and switch 4. The lever 1 l ofFIG. 1 is replaced by a rotatably journaled lever 14. When an operativeend of lever 14 comes in contact with the recess 8, the contacts 13a and13b of switch 13 are opened (FIG. 5). When the operative end of lever 14contacts the peripheral surface of cam 9, another operative end of lever14 forces movable contact 13a against opposed contact 13b, closing thecircuit (FIG. 6).

Referring again to the embodiment of FIG. 1, the mechanism according tothe present invention is arranged as above mentioned by way of example,upon or after opening the rear cover of the camera to load new film sothat the film frame number indicating mechanism is automatically ormanually returned to the graduation 7a for a fictitious shot. As aresult, the first operative end of the lever 11 falls into the recess 8of the cam 9. In this state, the lever 11 is rotated under action of thespring 12 clockwise as seen in FIG. 1. with the second operative endthereof forcing the movable contact 6a against the opposed contact 6b.Switch 6 is closed and the resistor 5 with its relatively low impedancevalue is inserted in parallel with the photosensitive element 3 (seeFIG. 2).

After new film has been loaded into the camera, and the rear cover ofthe camera is closed again, the fictitious shots are taken by operatingthe shutter button. When the camera shutter button is depressed foractuating the opening of the shutter after a frame of exposed film hasbeen transported, the control circuit 1a operates with an exposure timedetermined essentially only by the low resistance value of the resistor5 previously connected in parallel with photosensitive element 3. Theexposure time is relatively short because of the relatively lowresistance value of the resistor 5 even if the objective remains capped.Shutter closure occurs immediately after each release operation,allowing the immediate transport of the next frame .of exposed film asdescribed above.

After several fictitious shots, the first operative end of the lever 11is urged by an edge of the recess 8 from the position as shown by FIG. 2counterclockwise as seen in FIG. 2 against action of the spring 12 to aposition in which the first operative end rides on the periphery of thecam 9. Consequently, the second operative end of the lever 11 retractsout of a region in which the second operative end acts upon the movablecontact 6a of the switch 6, opening the switch 6 (this corresponds tothe state as shown by FIG. 3). Thus, the automatic exposure time controlcircuit restores to its normal state so as to control the exposure timein accordance with light intensity of an object to be photographed whichis detected by the photosensitive element 3.

In the embodiment as shown by FIG. 4, the second operative end of thelever 14 is out of engagement with the movable contact 13a of theswitch13 during operation of fictitious shots since the first operativeend of the lever 14 falls into the recess 8 of the cam 9 and, as aresult, the lever 14 is rotated under action of the spring 12 clockwiseas seen in FIG. 4. Consequently, the switch 13 is in opened state andthe operating circuits such as the shutter closure starting circuit 1 iskept from energization. When the shutter closure startin g circuit 1 isof the type such that the electromagnetic mechanism to start shutterclosure is deenergized and thereby shutter closure is started, i.e., ofso-called demagnetization type, the shutter closure occurs substantiallyat the moment of the shutter opening operation. The manner in which thisembodiment operates during operation of fictitious shots is, therefore,identical to the manner of operation in theprevious embodimet and isillustrated in FIG. 5. The lever 14 is urged by the edge of the cam 9,at the position on which the indicator disk 7 indicates the fraguationcorresponding to zero value, counter-clockwise as seen in FIG. againstaction of the spring 12 while the second operative end of said lever 14forces the movable contact 13a against the opposed contact 1312 so as toclose the switch 13. When the source switch 4 operatively associatedwith operation such as transport of film is closed, connection betweenthe power source battery 2 and the circuit section is established andthereafter the exposure time control is normally effected.

With the mechanism of the present invention, as seen from the foregoingdescription, a shutter closure urging circuit is inserted into theshutter closure starting circuit in the form that a resistor circuit isinserted in parallel to the photosensitive element and thereby shutteroperation is effected under control of a relatively short exposure timewhich is, in turn, determined by the resistor included in said shutterclosure urging circuit substantially irrelative to the intensity oflight incident upon said photosensitive element. And it is possible toactivate the automatic exposure time control means in the state ofshutter operation for a short time even when the objective is cappedduring operation of fictitious shots. Thus, operation of fictitiousshots is easily done without any inconvenience.

Although the shutter closure urging circuit in the mechanism accordingto the present invention has been shown as two embodiments, the oneinserted in parallel to the photosensitive element and the otherserially inserted into the source circuit, this circuit may be seriallyor parallelly inserted at the positions in the shutter closure startingcircuit that influence the time point of shutter closure starting suchas in series or in parallel to a trigger bias circuit included in aswitching transistor circuit, an electromagnet or an output transistorincluded in a circuit fo energization of said electromagnet withoutdeparture from the scope of the invention.

What is claimed is: g

l. A photographic camera having an automatic exposure control means, thecombination comprising:

a. an exposure time control circuit including a shutter closure startingcircuit;

b. a shutter closure urging circuit operably connected into said shutterclosure starting circuit and having connected therein switch means torender effective or ineffective said shutter closure urging circuit;

c. film frame number indicating mechanism having a range for usableframe indications and at least one non-usable frame indication; and

d. means for actuating said switch means to render effective saidshutter closure urging circuit in response to said indicating mechanismbeing positioned at said non-usable frame indication and for renderingineffective said shutter closure urging circuit in response to saidindicating mechanism being positioned at said at least one usable frameindication.

2. A photographic camera with an automatic exposure control means, anexposure time control circuit having a shutter closure starting circuit,and a film frame number indicating mechanism having non-usable frameindication and usable frame indication, the improvement comprising:

a. a shutter closure urging circuit operably connected into said shutterclosure starting circuit and having connected therein a switch means torender effective and inffective said shutter closure urging circuit; andI b. means for actuating said switch means to render effective saidshutter closure urging circuit in response to said indicating mechanismbeing positioned at said non-usable frame indication and for renderingineffective said shutter closure urging circuit inresponse to saidindicating mechanism being positioned at said'usable frame indication.

3. A photographic camera with an automatic exposure control means, anexposure time control circuit for initiating the closure of the camerashutter and a film frame number indicating mechanism having nonusableframe indication and usable frame indication, the improvementcomprising:

a. a shutter closure urging circuit operably connected into saidexposure time control circuit and having connected therein a switchmeans to render effective and ineffective said shutter closure urgingcircuit; and

b. means for actuating said switch means to render effective saidshutter closure urging circuit in response to said indicating mechanismbeing positioned at said non-usable frame indication and for renderingineffective said shutter closure urging circuit in response to saidindicating mechanism positioned at said usable frame indication.

4. A photographic camera according to claim 3 wherein said means foractuating comprises a cam movable with changes in said frame numberindicating mechanism and a mechanical linkage actuated by said cam foractuating said switch means.

5. A photographic camera according to claim 4 wherein said switch meanscomprises a mechanical switch.

6. A photographic camera according to claim 3 wherein said cameracomprises a photosensitive element operatively coupled to said exposuretime control circuit for controlling the same in accordance with theamount of received light, said shutter closure urging circuit comprisingan impedance element coupled in parallel with said photosensitiveelement through said switch means.

7. A photographic camera according to claim 3 wherein said cameracomprises a photosensitive element operatively coupled to said exposuretime control circuit for controlling the same in accordance with theamount of received light, said shutter closure urging circuit comprisingsaid switch means coupled for connecting and disconnecting saidphotosensitive element from said exposure time control circuit.

* k In mg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PatentNo. 3,769,886 D d NOV. 6, 1973 Naoyuki Uno; Katsuhiko Nomura; TadazumiSakazaki; Inventor(s) Koichiro Watanabe; Katsuhiko Miyata and FumioUrano It is certified that error appears in the above-identified patentand that said Letters Patent are hereby corrected as shown below:

Col. 1, line 32, "embodiemnt" should read --embodiment--; W line 55,"batter" should read --battery--;

Col. 3, line 21, "embodimet" should read ---embodiment--;

line 24 "fraguation" should read --graduation-; line 59, "f0" shouldread -for--.

Signed and sealed this 23rd day of April 19714..

(SEAL) Attest:

EDWARD I ZJ LETGHEFQJR. C, I' IARSI'IALL DAI-IN Commissioner of PatentsAttesting Officer UNITED STATES PATENT OFFICE (5/69) CERTIFICATE OFCORRECTION Parent No. 3:769:886 D t d NOV. 6, 1973 Naoyuki Uno;Katsuhiko Nomura; Tadazumi Sakazaki; Invencm-(s) Koichiro Watanabe;Katsuhiko Miyata and Fumio Urano It is certified that error appears inthe above-identified patent and that said Letters Patent are herebycorrected as shown below:

Col. 1, line 32, "embodiemnt" should read --embodiment--; M line 55,"batter" should read --bat tery--;

Col. 3, line 21, "embodimet" should read ---embodiment--;

line 24, "iraguation" should read --graduation--; line 59, "f0" shouldread --for--.

Signed and sealed this 23rd day of April 19714..

( SEAL Attest:

EDWARD HJWJPJ'TCJ'cIER THr C MARSHALL DANN Attesting OfficerCommissioner of Patents

1. A photographic camera having an automatic exposure control means, thecombination comprising: a. an exposure time control circuit including ashutter closure starting circuit; b. a shutter closure urging circuitoperably connected into said shutter closure starting circuit and havingconnected therein switch means to render effective or ineffective saidshutter closure urging circuit; c. film frame number indicatingmechanism having a range for usable frame iNdications and at least onenon-usable frame indication; and d. means for actuating said switchmeans to render effective said shutter closure urging circuit inresponse to said indicating mechanism being positioned at saidnon-usable frame indication and for rendering ineffective said shutterclosure urging circuit in response to said indicating mechanism beingpositioned at said at least one usable frame indication.
 2. Aphotographic camera with an automatic exposure control means, anexposure time control circuit having a shutter closure starting circuit,and a film frame number indicating mechanism having non-usable frameindication and usable frame indication, the improvement comprising: a. ashutter closure urging circuit operably connected into said shutterclosure starting circuit and having connected therein a switch means torender effective and inffective said shutter closure urging circuit; andb. means for actuating said switch means to render effective saidshutter closure urging circuit in response to said indicating mechanismbeing positioned at said non-usable frame indication and for renderingineffective said shutter closure urging circuit in response to saidindicating mechanism being positioned at said usable frame indication.3. A photographic camera with an automatic exposure control means, anexposure time control circuit for initiating the closure of the camerashutter and a film frame number indicating mechanism having non-usableframe indication and usable frame indication, the improvementcomprising: a. a shutter closure urging circuit operably connected intosaid exposure time control circuit and having connected therein a switchmeans to render effective and ineffective said shutter closure urgingcircuit; and b. means for actuating said switch means to rendereffective said shutter closure urging circuit in response to saidindicating mechanism being positioned at said non-usable frameindication and for rendering ineffective said shutter closure urgingcircuit in response to said indicating mechanism positioned at saidusable frame indication.
 4. A photographic camera according to claim 3wherein said means for actuating comprises a cam movable with changes insaid frame number indicating mechanism and a mechanical linkage actuatedby said cam for actuating said switch means.
 5. A photographic cameraaccording to claim 4 wherein said switch means comprises a mechanicalswitch.
 6. A photographic camera according to claim 3 wherein saidcamera comprises a photosensitive element operatively coupled to saidexposure time control circuit for controlling the same in accordancewith the amount of received light, said shutter closure urging circuitcomprising an impedance element coupled in parallel with saidphotosensitive element through said switch means.
 7. A photographiccamera according to claim 3 wherein said camera comprises aphotosensitive element operatively coupled to said exposure time controlcircuit for controlling the same in accordance with the amount ofreceived light, said shutter closure urging circuit comprising saidswitch means coupled for connecting and disconnecting saidphotosensitive element from said exposure time control circuit.